The present invention relates generally to the field of security latching mechanisms.
In recent years, a variety of latch mechanisms have been conceived and utilized for screen doors, storm doors, and the like, in which a swingably supported handle engageable from opposite sides of the door is utilized to releasably actuate a spring-urged latch from a latching position to a non-latching position.
One such known embodiment is disclosed in U.S. Pat. No. 2,317,300 in which a tubular casing is adapted to fit snugly within a cylindrical aperture in the door, this casing having an integrally formed escutcheon plate for one side of the door extending at right angles, and a double-ended handle extending through the tubular casing and intermediately pivoted for movement of an associated latch dog into an operative position by a compression spring. The escutcheon plate mounts a swingable lock piece that may be manually moved to a position opposing movement of the latch dog out of its operative position. In this patent arrangement, it is readily apparent that the latch mechanism is limited with respect to installations in which the manually operable lock piece and latch dog are located on the same side of the door. There are installations in which it may be desirable to have the manually operable lock piece on the opposite side of the door from that of the latch dog.
The present invention provides an improvement in latch mechanisms, as exemplified by the above patent, and provides a combination of components which are so designed and arranged that they can be operatively assembled, without limiting their function and operating efficiency, to meet a variety of different installation requirements. The components are readily susceptible of assembly for use on in or out swinging doors, as well as for right and left hand doors. The latch mechanism of the present invention might therefore be aptly referred to as a "4-ways" latch mechanism.
This installation versatility of the present invention is made possible by a unique unit assembly of a casing and pivotally supported double-ended handle with a latch dog, which is selectively mountable on the door in relatively reversible positions, and by the provision of interchangeable escutcheon plates which are supported on the door independently of the casing and handle unit, one of the escutcheon plates mounting a manually operable dogging member for opposing movement of the handle in an unlatching direction, irrespective of whether such one escutcheon plate is mounted on the inner or outer surface of the door.